/Engine/Source/Runtime/Core/Public/HAL/MallocBinned.h
InPageSize - First parameter is page size, all allocs from BinnedAllocFromOS() MUST be aligned to this size AddressLimit - Second parameter is estimate of the range of addresses expected to be returns by BinnedAllocFromOS(). Binned Malloc will adjust its internal structures to make lookups for memory allocations O(1) for this range. It is ok to go outside this range, lookups will just be a little slower
FMallocBinned ( uint32 InPageSize, uint64 AddressLimit )